Its "Star Wars" and Marvel comic-book movies will be included in the service, making it the only way to stream those movies on demand in the U.S. as part of a monthly subscription. (So, not on Netflix.)

A price hasn't been announced yet. The service is expected in late 2019 after Disney's current deal with Netflix expires.

Previously Disney announced the inclusion of just Disney and Pixar movies and Disney TV shows. Adding the "Star Wars" and Marvel movies could make the new service appealing to teenagers and adults, not just families with young children. The Marvel movies include the "Avengers" and "Guardians of the Galaxy" franchises.

The service will also have original Disney movies, TV series and shorts. Disney CEO Bob Iger said thousands of TV episodes and hundreds of movies will be available, though shows from Disney's ABC network aren't coming to the service.

Disney said last month that it was considering moving "Star Wars" and Marvel to the new service, but a decision wasn't announced until Thursday.

Disney's offering is one of many online film and TV options coming from entertainment and tech companies, with more in the works. Disney, for example, is also launching an ESPN sports streaming service early next year. It won't replicate what's on ESPN, for now, so it's expected to be somewhat niche.

The company's shares slid $4.05, or 4 percent, to $97.46 in Thursday afternoon trading. Investors may have sold because Iger said earnings per share for this fiscal year will be similar to the level for the year that ended on Oct. 1, 2016. Wall Street analysts had predicted growth.